A massively multiplayer online game (MMOG or MMO) is an online game which is capable of supporting large numbers of players, typically from hundreds to thousands, simultaneously in the same instance (or world). MMOs usually feature a huge, persistent open world, although some games differ. These games can be found for most network-capable platforms, including the personal computer, video game console, or smartphones and other mobile devices.
MMOs can enable players to cooperate and compete with each other on a large scale, and sometimes to interact meaningfully with people around the world. They include a variety of gameplay types, representing many video game genres.